I am adding a bathroom in my basement complete with toilet, tub,
shower, and sink. I believe I have the drainage system down but I
don't quite have the venting figured out. I bought a book with about
10 full color pages on how to vent plumbing properly but I still am
having trouble figuring out what I need to do exactly. If you open the
pdf or jpeg at http://www.kcengineer.com/piping.jpg or
http://www.kcengineer.com/piping.pdf you will see my current layout. I
have added letter to the pipes to aid in telling me where to come off
for vents. If I understand correctly, I would only need to add a vent
to the pipe labeled C which is between the shower trap and wye for the
tub. Doing that I assume would allow the shower, tub, and toilet to
pull air from that vent and not sucking water out of a trap. The sink
will have a mechanical vent you can buy for about $5. Then again, maybe
I don't need any vents as I did run 4 inch all the way to the toilet
and 2 inch all the way to each fixture so the pipe may just vent itself
because the top half would never be full. I am confused as what to do;
this is my only option for layout of piping because of space
restriction. By the way, the longest pipe is D, about 7' long. The
rest are all 3' or less sections. Thanks for any advice!